Ok, this thread has been open for quite some time and it seems the graphics still needs some work *cough*
I have the distinct impression you are looking at the wrong people for creating a good GUI, this is gaming; turn to javadesktop!
I am one of the main authors for the UICompiler project that allows you to create good looking GUIs in no time, just use the right tools
ps. need any test-drivers ? If I like it I might take some time for a gui